Cooling Mode of Condenser in High and Low Temperature Test Chamber
High and low temperature test chamber is a common temperature test equipment in environmental test equipment, which is suitable for high temperature and low temperature reliability test of industrial products. The working principle of refrigeration in the high and low temperature test chamber is that the refrigerant flows out of the condenser under high pressure, passes through the throttling mechanism (capillary, thermal expansion valve, etc.), reduces its pressure, and then enters the evaporator. When the refrigeration medium enters the evaporator, it is a two-phase mixture (liquid and gas), which evaporates and absorbs heat under low temperature conditions in the evaporator. It then enters the condenser, where heat is released and condensed into a liquid. Xenon lamp aging test chamber uses xenon lamp with long arc as light source, which can provide corresponding environmental simulation and accelerated test for scientific research, product development and quality control. The vehicle environment simulation laboratory can simulate the test environment of engine cold start, vehicle high and low temperature, wind, frost, rain, snow, vehicle emission test, etc.
According to different refrigeration media, the cooling mode of the high and low temperature test chamber condenser can be divided into three types: air cooling, water cooling and liquid nitrogen refrigeration. Their medium is refrigerant, water and liquid nitrogen. Different media correspond to different evaporation temperatures, the same medium under different evaporation pressure, evaporation temperature is not the same.
The different cooling methods of the condenser in the high and low temperature test chamber make the components of the refrigeration different. The air cooling method consists of compressor, various refrigeration accessories, condenser, oil separator and so on. The water cooling method consists of: chiller, cooling tower, freezing pump and auxiliary equipment. Liquid nitrogen is composed of: liquid nitrogen tank, pressure transmitter, pressure gauge, flow meter, level meter, ultra-low temperature solenoid valve and so on.
No matter what kind of cooling method is used in the high and low temperature test chamber condenser, high reliability and safety are the most basic requirements. Instrument test equipment of Lab Companion can provide a variety of condenser cooling methods according to customer needs.
In addition to the high and low temperature test chamber, instrument of Lab Companion also produces all kinds of temperature and humidity test chamber, constant temperature and humidity test equipment, aging chamber (ultraviolet, xenon lamp, ozone aging chamber), thermal shock test chamber, high temperature aging machine and other equipment, all the equipment is produced according to national standards and industry specifications.
High and Low Temperature Test Chamber Requirements Specified in the Standard
The test chamber requirements formulated according to relevant standards should meet the following two points:
1. The temperature and humidity in the high and low temperature test chamber are monitored by the sensor installed in the working space. For the test of the heat dissipation test sample, the installation position of the sensor is formulated in the GB/T2421-1999 standard.
2, The temperature and relative humidity of the working space are required to be constant within the nominal value and its specified tolerance range, and the influence of the test sample should also be considered during the test.
Heat dissipation test sample test:
The volume of the high and low temperature test chamber should be at least 5 times the total volume of the test sample, the distance between the test sample and the internal wall of the test chamber should be selected according to the provisions of GB/T2423.2-2001 Appendix A (standard appendix), the wind speed in the chamber should not exceed 1M/S, and the structure of the mounting frame or support frame of the test chamber sample should simulate the real conditions in use as much as possible. Or otherwise, the effect of the sample mounting rack on the exchange of heat and moisture between the test sample and the surrounding space should be reduced to a minimum, and the relevant specifications may also specify dedicated mounting racks.
Test severity level:
The severity grade of the test chamber consists of the test temperature, relative humidity and test time, and is specified by the relevant specifications. The combination of temperature and relative humidity can be selected from the following values:
a, 30℃±2℃ 93%±3%
b, 30℃±2℃ 85%±3%
c, 40℃±2℃ 93%±3%
d, 40℃±2℃ 85%±3%
During the test, the test chamber shall be at the temperature and humidity of the laboratory, and the test sample at the ambient temperature of the laboratory shall be placed in the normal position or other specified position in the laboratory in an unpacked, unenergized, "ready for use" state, under certain circumstances (e.g. The relevant specifications may allow the test sample to be directly sent into the test chamber under the treated test conditions, but the test sample must be prevented from producing condensation, the temperature in the test chamber should be adjusted to a predetermined severity level, the time should ensure that the test sample reaches temperature stability, the test time should be calculated from the specified conditions, if the relevant specifications require, the test sample can be energized or worked in the conditional test phase, and the relevant specifications should specify the working conditions and working time or cycle of the test sample during the test. At the end of the conditional test, the test sample should still be left in the test chamber and the chamber should be adjusted to the standard atmospheric conditions of the test. The relative humidity should be reduced first, and the time should not exceed 2 hours. The temperature change rate in the test chamber should not exceed 1℃/min on average within 5min, and the relative humidity during temperature regulation should not exceed 75%. After the conditional test, the test sample should enter the recovery procedure.
PCB Performs Accelerated Tests of Ion Migration and CAF Through HAST
PCB In order to ensure its long-term use quality and reliability, need to carry out SIR (Surface Insulation Resistance) surface insulation resistance test, through its test method to find out whether the PCB will occur MIG(ion migration) and CAF(glass fiber anode leakage) phenomenon, Ion migration is performed in a humidified state (e.g. 85℃/85%R.H.) with a constant bias (e.g. 50V), the ionized metal moves between the opposite electrodes (cathode to anode growth), the relative electrode is reduced to the original metal and precipitated dendritic metal phenomenon, often resulting in short circuit, ion migration is very fragile, the current generated at the moment of power will make the ion migration itself dissolves and disappears, MIG and CAF commonly used norms: IPC-TM-650-2.6.14., IPC-SF-G18, IPC-9691A, IPC-650-2.6.25, MIL-F-14256D, ISO 9455-17, JIS Z 3284, JIS Z 3197... But its test time is often 1000h, 2000h, for the cyclical products slow emergency, and HAST is a test method is also the name of the equipment, HAST is to improve environmental stress (temperature, humidity, pressure), in the unsaturated humidity environment (humidity: 85%R.H.) Speed up the test process to shorten the test time, used to assess PCB pressing, insulation resistance, and the moisture absorption effect of related materials, shorten the test time of high temperature and humidity (85℃/ 85%R.H. /1000h→110℃/ 85%R.H. /264h), the main reference specifications of PCB HAST test are: JESD22-A110-B, JCA-ET-01, JCA-ET-08.
HAST Accelerated Life Mode:
★ Increase temperature (110℃, 120℃, 130℃)
★ Maintain high humidity (85%R.H.)
Taken the pressure (110 ℃ / / 0.12 MPa, 120 ℃, 85% / 85% / 85% 0.17 MPa, 130 ℃ / / 0.23 MPa)
★ Extra bias (DC)
HAST test conditions for PCB:
1. Jca-et-08:110, 120, 130 ℃/85%R.H. /5 ~ 100V
2. High TG epoxy multilayer board: 120℃/85%R.H./100V, 800 hours
3. Low inductance multilayer board: 110℃/85% R.H./50V/300h
4. Multi-layer PCB wiring, material: 120℃/85% R.H/100V/ 800h
5. Low expansion coefficient & low surface roughness halogen-free insulation material: 130℃/ 85% R.H/12V/240h
6. Optically active covering film: 130℃/ 85% R.H/6V/100h
7. Heat hardening plate for COF film: 120℃/ 85% R.H/100V/100h
Lab Companion HAST High Acceleration Stress Test System (JESD22-A118/JESD22-A110)
The HAST independently developed by Macro Technology fully owns independent intellectual property rights, and the performance indicators can fully benchmark foreign brands. It can provide single-layer and double-layer models and two series of UHAST BHAST. It solves the problem of long-term dependence on imports of this equipment, long delivery time of imported equipment (up to 6 months) and high price. High Accelerated Stress Testing (HAST) combines high temperature, high humidity, high pressure, and time to measure the reliability of components with or without electrical bias. HAST testing accelerates the stress of more traditional testing in a controlled way. It is essentially a corrosion failure test. Corrosion-type failure is accelerated, and defects such as packaging seals, materials and joints are detected in a relatively short time.
Reliability of Ceramic Substrate
Ceramic PCB (Ceramic Substrate) refers to a special process plate where copper foil is directly bonded to the surface (single or double) of alumina (Al2O3) or aluminum nitride (AlN) ceramic substrate at high temperature. The ultra-thin composite substrate has excellent electrical insulation performance, high thermal conductivity, excellent soldering and high adhesion strength, and can be etched into a variety of graphics like PCB board, with great current carrying capacity. Therefore, the ceramic substrate has become the basic material of high-power electronic circuit structure technology and interconnect technology, which is suitable for products with high caloric value (high-brightness LED, solar energy), and its excellent weather resistance can be applied to harsh outdoor environments.
Main application products: high power LED carrier board, LED lights, LED street lights, solar inverter
Ceramic substrate features:
Structure: Excellent mechanical strength, low warping, thermal expansion coefficient close to silicon wafer (aluminum nitride), high hardness, good processability, high dimensional accuracy
Climate: Suitable for high temperature and humidity environment, high thermal conductivity, good heat resistance, corrosion and wear resistance, UV& yellowing resistance
Chemistry: Lead-free, non-toxic, good chemical stability
Electrical: high insulation resistance, easy metallization, circuit graphics and strong adhesion
Market: Abundant materials (clay, aluminum), easy to manufacture, low price
PCB material thermal characteristics comparison (conductivity) :
Glass fiber board (traditional PCB) : 0.5W/mK, aluminum substrate: 1~2.2W/mK, ceramic substrate: 24[alumina]~170[aluminum nitride]W/mK
Material heat transfer coefficient (unit W/mK) :
Resin: 0.5, alumina: 20-40, silicon carbide: 160, aluminum: 170, aluminum nitride: 220, copper: 380, diamond: 600
Ceramic substrate process classification:
According to the line ceramic substrate process is divided into: thin film, thick film, low temperature co-fired multi-layer ceramic (LTCC)
Thin Film Process (DPC) : Precise control of component circuit design (line width and film thickness)
Thick film process (Thick film) : to provide heat dissipation and weather conditions
Low temperature co-fired multilayer ceramic (HTCC) : The use of glass ceramics with low sintering temperature, low melting point, high conductivity of precious metal co-fired characteristics, multi-layer ceramic substrate) and assembly.
Low temperature co-fired multilayer ceramics (LTCC) : Stack several ceramic substrates and embed passive components and other ics
Thin film ceramic substrate process:
· Pretreatment → sputtering → photoresistance coating → exposure development → line plating → film removal
· Lamination → hot pressing → degreasing → substrate firing → circuit pattern formation → circuit firing
· Lamination → surface printed circuit pattern → hot pressing → degreasing → co-firing
· Printed circuit graphics → lamination → hot pressing → degreasing → co-firing
Ceramic substrate reliability test conditions:
Ceramic substrate high temperature operation: 85℃
Ceramic substrate low temperature operation: -40℃
Ceramic substrate cold and thermal shock:
1. 155℃(15min)←→-55℃(15min)/300cycle
2. 85 ℃ (30 min) please - - 40 ℃ (30 min)/RAMP: 10 min (12.5 ℃ / min) / 5 cycle
Ceramic substrate adhesion: Stick to the surface of the board with 3M#600 tape. After 30 seconds, tear quickly in a 90° direction with the surface of the board.
Ceramic substrate red ink experiment: Boil for one hour, impermeable
Test equipment:
1.High and low temperature humid heat test chamber
2. Three-box gas type cold and heat shock test chamber
IEC-60068-2 Combined Test of Condensation and Temperature and Humidity
Difference of IEC60068-2 damp heat test specifications
In the IEC60068-2 specification, there are a total of five kinds of humid heat tests, in addition to the common 85℃/85%R.H., 40℃/93%R.H. In addition to fixed-point high temperature and high humidity, there are two more special tests [IEC60068-2-30, IEC60068-2-38], these two are alternating wet and humid cycle and temperature and humidity combined cycle, so the test process will change temperature and humidity, and even multiple groups of program links and cycles, applied in IC semiconductors, parts, equipment, etc. To simulate the outdoor condensation phenomenon, evaluate the material's ability to prevent water and gas diffusion, and accelerate the product's tolerance to deterioration, the five specifications were organized into a comparison table of the differences in the wet and heat test specifications, and the test points were explained in detail for the wet and heat combined cycle test, and the test conditions and points of GJB in the wet and heat test were supplemented.
IEC60068-2-30 alternating humid heat cycle test
This test uses the test technique of maintaining humidity and temperature alternating to make moisture penetrate into the sample and cause condensation (condensation) on the surface of the product to be tested, so as to confirm the adaptability of the component, equipment or other products in use, transportation and storage under the combination of high humidity and temperature and humidity cyclic changes. This specification is also suitable for large test samples. If the equipment and the test process need to keep the power heating components for this test, the effect will be better than IEC60068-2-38, the high temperature used in this test has two (40 ° C, 55 ° C), the 40 ° C is to meet most of the world's high temperature environment, while 55 ° C meets all the world's high temperature environment, the test conditions are also divided into [cycle 1, cycle 2], In terms of severity, [Cycle 1] is higher than [Cycle 2].
Suitable for side products: components, equipment, various types of products to be tested
Test environment: the combination of high humidity and temperature cyclic changes produces condensation, and three kinds of environments can be tested [use, storage, transportation ([packaging is optional)]
Test stress: Breathing causes water vapor to invade
Whether power is available: Yes
Not suitable for: parts that are too light and too small
Test process and post-test inspection and observation: check the electrical changes after moisture [do not take out the intermediate inspection]
Test conditions: Humidity: 95%R.H.[Temperature change after high humidity maintenance](low temperature 25±3℃←→ high temperature 40℃ or 55℃)
Rising and cooling rate: heating (0.14℃/min), cooling (0.08 ~ 0.16℃/min)
Cycle 1: Where absorption and respiratory effects are important features, the test sample is more complex [humidity not less than 90%R.H.]
Cycle 2: In the case of less obvious absorption and respiratory effects, the test sample is simpler [humidity is not less than 80%R.H.]
IEC60068-2 damp heat test specification difference comparison table
For component type parts products, a combination test method is used to accelerate the confirmation of the test sample's resistance to degradation under high temperature, high humidity and low temperature conditions. This test method is different from the product defects caused by respiration [dew, moisture absorption] of IEC60068-2-30. The severity of this test is higher than that of other humid heat cycle tests, because there are more temperature changes and [respiration] during the test, the cycle temperature range is larger [from 55℃ to 65℃], and the temperature change rate of the temperature cycle is faster [temperature rise: 0.14 ° C /min becomes 0.38 ° C /min, 0.08 ° C /min becomes 1.16 ° C /min], in addition, different from the general humid heat cycle, the low temperature cycle condition of -10 ° C is added to accelerate the breathing rate and make the water condensed in the gap of the substitute freeze, which is the characteristic of this test specification. The test process allows the power test and the applied load power test, but it can not affect the test conditions (temperature and humidity fluctuation, rising and cooling rate) because of the heating of the side product after power. Due to the change of temperature and humidity during the test process, there can not be condensation water droplets on the top of the test chamber to the side product.
Suitable for side products: components, metal components sealing, lead end sealing
Test environment: combination of high temperature, high humidity and low temperature conditions
Test stress: accelerated breathing + frozen water
Whether it can be powered on: it can be powered on and external electric load (it can not affect the conditions of the test chamber because of power heating)
Not applicable: Can not replace moist heat and alternating humid heat, this test is used to produce defects different from respiration
Test process and post-test inspection and observation: check the electrical changes after moisture [check under high humidity conditions and take out after test]
Test conditions: damp heat cycle (25 please - 65 + 2 ℃ / 93 + / - 3% R.H.) please - low temperature cycle (25 please - 65 + 2 ℃ / 93 + 3% R.H. - - 10 + 2 ℃) X5cycle = 10 cycle
Rising and cooling rate: heating (0.38℃/min), cooling (1.16 ℃/min)
Heat and humidity cycle (25←→65±2℃/93±3%R.H.)
Low temperature cycle (25←→65±2℃/93±3%R.H. →-10±2℃)
GJB150-09 damp heat test
Instructions: The wet and heat test of GJB150-09 is to confirm the ability of equipment to withstand the influence of hot and humid atmosphere, suitable for equipment stored and used in hot and humid environments, equipment prone to high humidity, or equipment that may have potential problems related to heat and humidity. Hot and humid locations can occur throughout the year in the tropics, seasonally in mid-latitudes, and in equipment subjected to combined pressure, temperature and humidity changes, with special emphasis on 60 ° C /95%R.H. This high temperature and humidity does not occur in nature, nor does it simulate the dampness and heat effect after solar radiation, but it can find the parts of the equipment with potential problems, but it cannot reproduce the complex temperature and humidity environment, evaluate the long-term effect, and can not reproduce the humidity impact related to the low humidity environment.
Relevant equipment for condensation, wet freezing, wet heat combined cycle test: constant temperature and humidity test chamber
Purpose of Temperature Shock Test
Reliability environmental test In addition to high Temperature, low temperature, high temperature and high humidity, temperature and humidity combined cycle, temperature Shock (cold and hot Shock) is also a common test project, temperature shock Testing (Thermal Shock Testing, Temperature Shock Testing, referred to as: TST), the purpose of the temperature shock test is to find out the design and process defects of the product through the severe temperature changes that exceed the natural environment [temperature variability greater than 20℃/min, and even up to 30 ~ 40℃/min], but there is often a situation where the temperature cycle is confused with the temperature shock. "Temperature cycle" means that in the process of high and low temperature change, the temperature change rate is specified and controlled; The temperature change rate of "temperature shock" (hot and cold shock) is not specified (Ramp Time), mainly requires Recovery Time, according to the IEC specification, there are three kinds of temperature cycle test methods [Na, Nb, NC]. Thermal shock is one of the three [Na] test items [rapid temperature change with specified conversion time; medium: air], the main parameters of temperature shock (thermal shock) are: High temperature and low temperature conditions, residence time, return time, number of cycles, in high and low temperature conditions and residence time the current new specification will be based on the surface temperature of the test product, rather than the air temperature in the test area of the test equipment.
Thermal shock test chamber:
It is used to test the material structure or composite material, in an instant under the continuous environment of extremely high temperature and extremely low temperature, the degree of tolerance, so as to test the chemical changes or physical damage caused by thermal expansion and contraction in the shortest time, the applicable objects include metal, plastic, rubber, electronic.... Such materials can be used as the basis or reference for the improvement of its products.
The cold and thermal shock (temperature shock) test process can identify the following product defects:
Different expansion coefficient caused by the stripping of the joint
Water enters after cracking with different expansion coefficient
Accelerated test for corrosion and short circuit caused by water infiltration
According to the international standard IEC, the following conditions are common temperature changes:
1. When the equipment is transferred from a warm indoor environment to a cold outdoor environment, or vice versa
2. When the equipment is suddenly cooled by rain or cold water
3. Installed in the outside airborne equipment (such as: automobile, 5G, outdoor monitoring system, solar energy)
4. Under certain transport [car, ship, air] and storage conditions [non-air-conditioned warehouse]
Temperature impact can be divided into two types of two-box impact and three-box impact:
Instructions: Temperature impact is common [high temperature → low temperature, low temperature → high temperature] way, this way is also called [two-box impact], another so-called [three-box impact], the process is [high temperature → normal temperature → low temperature, low temperature → normal temperature → high temperature], inserted between the high temperature and low temperature, to avoid adding a buffer between the two extreme temperatures. If you look at the specifications and test conditions, there is usually a normal temperature condition, the high and low temperature will be extremely high and very low, in the military specifications and vehicle regulations will see that there is a normal temperature impact condition.
IEC temperature shock test conditions:
High temperature: 30, 40, 55, 70, 85, 100, 125, 155℃
Low temperature: 5, -5, -10, -25, -40, -55, -65℃
Residence time: 10min, 30min, 1hr, 2hr, 3hr(if not specified, 3hr)
Temperature shock residence time description:
The Dwell Time of temperature shock in addition to the requirements of the specification, some will depend on the weight of the test product and the surface temperature of the test product
The specifications of the thermal shock residence time according to weight are:
GJB360A-96-107, MIL-202F-107, EIAJ ED4701/100, JASO-D001... Let's wait.
The thermal shock residence time is based on the surface temperature control specifications: MIL-STD-883K, MIL-STD-202H(air above the test object)
MIL883K-2016 requirements for [temperature shock] specification:
1. After the air temperature reaches the set value, the surface of the test product needs to arrive within 16 minutes (residence time is not less than 10min).
2. High temperature and low temperature impact are more than the set value, but not more than 10℃.
Follow-up action of IEC temperature shock test
Reason: The IEC temperature test method is best considered as part of a series of tests, because some failures may not be immediately apparent after the test method is completed.
Follow-up test items:
IEC60068-2-17 Tightness test
IEC60068-2-6 Sinusoidal vibration
IEC60068-2-78 Steady Humid heat
IEC60068-2-30 Hot and humid temperature cycle
Tin whisker (whisker) temperature impact test conditions finishing:
1. - 55 (+ 0 / -) 10 ℃ please - 85 (+ / - 0) 10 ℃, 20 min / 1 cycle (500 cycle check again)
1000 cycles, 1500 cycles, 2000 cycles, 3000 cycles
2. 85(±5)℃←→-40(+5/-15)℃, 20min/1cycle, 500cycles
3.-35±5℃←→125±5℃, dwell for 7min, 500±4cycles
4. - 55 (+ 0 / -) 10 ℃ please - 80 (+ / - 0) 10 ℃, 7 min reside, 20 min / 1 cycle, 1000 cycles
Thermal shock testing machine product features:
Defrosting frequency: defrosting every 600cycles [Test condition: +150℃ ~ -55℃]
Load adjustment function: The system can automatically adjust according to the load of the product to be tested, without manual setting
High weight load: Before the equipment leaves the factory, use aluminum IC(7.5Kg) for load simulation to confirm that the equipment can meet the demand
Temperature shock Sensor location: The air outlet and return air outlet in the test area can be selected or both can be installed, which conforms to the MIL-STD test specification. In addition to meeting the requirements of the specification, it is also closer to the impact effect of the test product during the test, reducing the test uncertainty and distribution uniformity.
Solar Module EVA Film Introduction 1
In order to improve the power generation efficiency of solar cell modules, provide protection against the loss caused by environmental climate change, and ensure the service life of solar modules, EVA plays a very important role. EVA is non-adhesive and anti-adhesive at room temperature. After hot pressing under certain conditions during the solar cell packaging process, EVA will produce melt bonding and adhesive curing. The cured EVA film becomes completely transparent and has quite high light transmittance. The cured EVA can withstand atmospheric changes and has elasticity. The solar cell wafer is wrapped and bonded with the upper glass and lower TPT by vacuum lamination technology.
Basic functions of EVA film:
1. Secure the solar Cell and connecting circuit wires to provide cell insulation protection
2. Perform optical coupling
3. Provide moderate mechanical strength
4. Provide a heat transfer pathway
EVA Main features:
1. Heat resistance, low temperature resistance, moisture resistance and weather resistance
2. Good followability to metal glass and plastic
3. Flexibility & Elasticity
4. High light transmission
5. Impact resistance
6. Low temperature winding
Thermal conductivity of solar cell related materials: (K value of thermal conductivity at 27 ° C (300'K))
Description: EVA is used for the combination of solar cells as a follow-up agent, because of its strong follow-up ability, softness and elongation, it is suitable for joining two different expansion coefficient materials.
Aluminum: 229 ~ 237 W/(m·K)
Coated aluminum alloy: 144 W/(m·K)
Silicon wafer: 80 ~ 148 W/(m·K)
Glass: 0.76 ~ 1.38 W/(m·K)
EVA: 0.35W /(m·K)
TPT: 0.614 W/(m·K)
EVA appearance inspection: no crease, no stain, smooth, translucent, no stain edge, clear embossing
EVA material performance parameters:
Melting index: affects the enrichment rate of EVA
Softening point: The temperature point at which EVA begins to soften
Transmittance: There are different transmittance for different spectral distributions, which mainly refers to the transmittance under the spectral distribution of AM1.5
Density: density after bonding
Specific heat: the specific heat after bonding, reflecting the size of the temperature increase value when the EVA after bonding absorbs the same heat
Thermal conductivity: thermal conductivity after bonding, reflecting the thermal conductivity of EVA after bonding
Glass transition temperature: reflects the low temperature resistance of EVA
Breaking tension strength: The breaking tension strength of EVA after bonding reflects the mechanical strength of EVA after bonding
Elongation at break: the elongation at break at EVA after bonding reflects the tension of EVA after bonding
Water absorption: It directly affects the sealing performance of battery cells
Binding rate: The binding rate of EVA directly affects his impermeability
Peel strength: reflects the bond strength between EVA and peel
EVA reliability test purpose: to confirm the weather resistance, light transmission, bonding force, ability to absorb deformation, ability to absorb physical impact, damage rate of pressing process of EVA... Let's wait.
EVA aging test equipment and projects: constant temperature and humidity test chamber (high temperature, low temperature, high temperature and high humidity), high and low temperature chamber (temperature cycle), ultraviolet testing machine (UV)
VA Model 2: Glass /EVA/ conductive copper sheet /EVA/ glass composite
Description: Through the on-resistance electrical measurement system, the low resistance in EVA is measured. Through the change of the on-resistance value during the test, the water and gas penetration of EVA is determined, and the oxidation corrosion of copper sheet is observed.
After three tests of temperature cycle, wet freezing and wet heat, the characteristics of EVA and Backsheet change:
(↑ : up, ↓ : down)
After three tests of temperature cycle, wet freezing and wet heat, the characteristics of EVA and Backsheet change:
(↑ : up, ↓ : down)
EVA：
Backsheet：
Yellow↑
Inner layer yellow ↑
Cracking ↑
Cracks in the inner layer and PET layer ↑
Atomization ↑
Reflectivity ↓
Transparency ↓
Solar Module EVA Film Introduction 2
EVA-UV test:
Description: Test the attenuation ability of EVA to withstand ultraviolet (UV) irradiation, after a long time of UV irradiation, EVA film will appear brown, penetration rate decreased... And so on.
EVA environmental test project and test conditions:
Humid heat: 85℃ / RH 85%; 1,000 hrs
Thermal cycle: -40℃ ~ 85℃; 50 cycles
Wet freezing test: -40℃ ~ 85℃ / RH 85%; 10 times UV: 280~385nm/ 1000w/200hrs (no cracking and no discoloration)
EVA Test Conditions (NREL) :
High temperature test: 95℃ ~ 105℃/1000h
Humidity and heat: 85℃/85%R.H./>1000h[1500h]
Temperature cycle: -40℃←→85℃/>200Cycles
(No bubbles, no cracking, no desticking, no discoloration, no thermal expansion and contraction)
UV aging: 0.72W/m2, 1000 hrs, 60℃(no cracking, no discoloration) Outdoor: > California sunshine for 6 months
Example of EVA characteristics change under Damp heat test:
Discoloration, atomization, Browning, delamination
Comparison of EVA bond strength at high temperature and humidity:
Description: EVA film at 65℃/85%R.H and 85℃/85%R.H. The degradation of the bond strength was compared at 65℃/85%R.H under two different wet and hot conditions. After 5000 hours of testing, the degradation benefit is not high, but EVA at 85℃/85%R.H. In the test environment, the adhesion is quickly lost, and there is a significant reduction in bond strength in 250 hours.
EVA-HAST unsaturated pressurized vapor test:
Objective: Since EVA film needs to be tested for more than 1000 hours at 85℃/85%R.H., which is equal to at least 42 days, in order to shorten the test time and accelerate the test speed, it is necessary to increase the environmental stress (temperature & humidity & pressure) and speed up the test process in the environment of unsaturated humidity (85%R.H.).
Test conditions: 110℃/85%R.H./264h
EVA-PCT pressure digester test:
Objective: The PCT test of EVA is to increase the environmental stress (temperature & humidity) and expose EVA to wetting vapor pressure exceeding one atmosphere, which is used to evaluate the sealing effect of EVA and the moisture absorption status of EVA.
Test condition: 121℃/100%R.H.
Test time: 80h(COVEME) / 200h(toyal Solar)
EVA and CELL bond tensile force test:
EVA: 3 ~ 6Mpa Non-EVA material: 15Mpa
Additional information from EVA:
1. The water absorption of EVA will directly affect its sealing performance of the battery
2.WVTR < 1×10-6g/m2/day(NREL recommended PV WVTR)
3. The adhesive degree of EVA directly affects its impermeability. It is recommended that the adhesive degree of EVA and cell should be greater than 60%
4. When the bonding degree reaches more than 60%, thermal expansion and contraction will no longer occur
5. The bonding degree of EVA directly affects the performance and service life of the component
6. Unmodified EVA has low cohesion strength and is prone to thermal expansion and contraction leading to chip fragmentation
7.EVA peeling strength: longitudinal ≧20N/cm, horizontal ≧20N/cm
8. The initial light transmittance of the packaging film is not less than 90%, and the internal decline rate of 30 years is not less than 5%
What are the Safety Protection Systems of the High and Low Temperature Test Chamber?
1, Leakage/surge protection:Leakage circuit breaker leakage protection FUSE.RC electronic surge protection from Taiwan
2, The controller internal self-automatic detection and protection device
(1) Temperature/humidity sensor: The controller controls the temperature and humidity in the test area within the set range through the temperature and humidity sensor
(2) Controller overtemperature alarm: when the heating tube in the chamber continues to heat up and exceeds the temperature set by the internal parameters of the controller, the buzzer in it will alarm and need to be manually reset and reused
3, Fault detection control interface: external fault automatic detection protection Settings
(1) The first layer of high temperature overtemperature protection: operation control overtemperature protection Settings
(2) The second layer of high temperature and overtemperature protection: the use of anti-dry burning overtemperature protector to protect the system will not be heated all the time to burn the equipment
(3) Water break and air burning protection: humidity is protected by anti-dry burning overtemperature protector
(4) Compressor protection: refrigerant pressure protection and over-load protection device
4, Fault abnormal protection: when the fault occurs, cut off the control power supply and the fault cause indication and alarm output signal
5, Automatic water shortage warning: the machine water shortage active warning
6, Dynamic high and low temperature protection: with the setting conditions to dynamically adjust the high and low temperature protection value
Get A Quote
IPv6 network supported